Currently, there are anti-spam systems that are incorporated in and with email systems and programs. These anti-spam systems analyze the frequency and volume of inbound emails in order to distinguish spam emails and senders from valid ones. The systems generally prevent email spam by utilizing various known anti-spam techniques. These techniques are typically embedded in products, services and software of email systems. However, these techniques are not a complete solution to the ever-present and rising problems associated with spam emails.
Known techniques include actions performed by users of the email systems, programs implemented by an email administrator, and any other service that monitors email to prevent not only spam, but phishing and identify theft. Each of these techniques have their trade-offs in terms of ineffectiveness, e.g. high cost, high usage of system resources, incorrectly rejecting legitimate emails, not rejecting all spam, and other drawbacks.